Method of manufacturing watch cases



March 6, 1956 1.. w. VAN DERNOOT 2,735,951

METHOD OF MANUFACTURING WATCH CASES Filed Dec. 23, 19 55 9&

INVENTOR. Lo 14 WW DER/V007 United States Patent METHOD OF MANUFACTURING WATCH CASES Leo W. van Dernoot, Wilton, Conn., assignor to D. E. Makepeace Company, Attleboro, Mass., a corporation of Massachusetts Application December 23, 1953, Serial No. 400,079

2 Claims. (Cl. 29-179) The present invention relates to a method of manufacturing a watch case and more particularly to a method of manufacturing a watch case of the unitary frame type.

Watch cases of the unitary frame type, wherein the bezel, movement-housing and other watch case components are formed from a solid metal frame, are generally manufactured by first blanking a disc from flatstock, forming the disc into a frame, e. g. by pressing operations, and further blanking the center of the frame. With such preliminary operations preceding the subsequent milling of other watch case components, a very considerable portion of fiatstock including the blanked center disc remnants are lost to metal scrap. When the Hat stock from which the frames are formed consists of a bimetallic strip having a layer of precious metal such as rolled gold as a component thereof, it is apparent that such precious metal represents considerable costs lost to scrap since the recovery of such precious metal represents added expense and the precious metal inventory for the manufacture of such bimetallic flat stock must include allowances for precious metal lost to scrap.

It is an object of the present invention to provide a watch case frame and method of manufacture thereof which precludes the loss of a substantial amount of metal to scrap. It is another object of the present invention to provide a watch case frame having a precious metal layer and the method of manufacture thereof wherein very little of the precious metal is lost to scrap. It is a further object of the present invention to provide a method of manufacturing a preformed watch case frame characterized by the elimination of heretofore costly operations. Other objects and advantages of the present invention will become apparent from the description hereinafter following and the drawings forming a part hereof in which:

Figure 1 represents a cross-sectional view of a metal wire according to the present invention,

Figure 2 represents a perspective view, partly in section, of wire drawn into ornamental shape,

Figure 3 illustrates a frame according to the present invention, and

Figure 4 illustrates a cross-sectional view of a watch case manufactured according to the present invention.

The present invention relates to the manufacture of a watch case frame from wire stock, whereby the said wire is formed into a frame of circular, rectangular or other configuration and butt-joined e. g. by welding or soldering, thereby eliminating about 90% of the scrap and the costly operations heretofore required in the manufacture of watch cases of the unitary frame type.

Referring to Figure l, a precious metal allocated wire, e. g. gold allocated wire, characterized by a coating 1 of precious metal on only a portion of a base metal core 2 having a fiat side substantially across the Width thereof, is provided prior to subsequent forming operations. Such allocated wire may be manufactured by 2,736,951 Patented Mar. 6, 1956 coating a core with precious metal and thereafter slitting the coated core longitudinally thereof to provide a face or faces free of the precious metal coating. The allocated wire is then drawn, pressed or otherwise formed into any suitable cross-sectional configuration for ornamental purposes. Such ornamental shaping is preferably restricted to the coated surface as illustrated by Figure 2, although, of course, it may not be so restricted.

Figure 2 illustrates, in addition to the ornamental shaping of the precious metal coated surface, the forming of a longitudinal recess 3 in the coated surface at the edge of said wire adjacent the fiat side, said recess being formed as by drawing or pressing and having a coated surface. The recess 3 may be formed by drawing or pressing simultaneously with the ornamental shaping of said wire.

Figure 3 illustrates the subsequent step of forming the recessed wire of Figure 2 into a frame by buttjoining the free ends of the wire as by soldering or welding to provide a butt-joint 4. The joint 4 uniting the precious metal layers may be obscured by burnishing the joint to blend the precious metal so that the said joint is rendered invisible.

By forming the recessed frame in the manner above disclosed, the exactitudes of precision milling operations are eliminated since a uniformity and sharpness of the recess contour are provided by the simple preforming manner, i. e. by drawing or pressing said recess in the longitudinal wire prior to forming the frame. Moreover, it is desirable to provide a reflecting seat 5 and side wall 6 adjacent a watch glass subsequently fitted into said recess. In order to provide such reflecting surfaces by conventional methods, electroplating operations are conventionally resorted to which add still another unnecessary step to watch case manufacturing operations, and which necessitates electroplating the entire frame. Obviously, such additional operations are eliminated by the method of this invention.

Having provided the said recessed frame, a continuous groove 7 is formed into the side wall 6 for anchoring a watch glass or a packing member associated with the retention of the watch glass in said recess. In addition to the said groove 7, and spaced therefrom, the base metal 2 is subjected to a watch-movement housing forming operation by forming a transverse channel 8 having dimensions according to the size of the watch-movement employed, and another transverse channel 9 spaced from said housing channel 8 for embracing a closure means for the opposite opening of said frame. Basically, the groove 7, housing 8 and channel 9 are a plurality of spaced continuous transverse channels formed into the flat side of the base metal core.

From the above description, it is apparent that the watch case thereby formed eliminates costly blanking and milling operations and the scrapping of substantial amounts of precious metal.

What I claim is:

l. The method of watch case manufacture comprising forming a wire having a precious metal coating on a base metal core, forming a flat side substantially across the width of said wire and free of said coating, recessing a coated edge of said wire adjacent said flat side, forming a frame from said wire by butt-joining the free ends of said wire, forming a plurality of continuous spaced channels into said fiat side.

2. The method of watch case manufacture comprising forming a wire having a precious metal coating on a base metal core, forming a flat side free of said coating substantially across the width of said wire, recessing a coated edge of said wire adjacent said fiat side, forming a frame from said wire by butt-joining the free ends of said wire, forming a continuous groove in said recess 3 transversally Of said frame, and forming a plurality of 365,826 continuous spaced channels into said fiat side. 394,603 404,956 7 References Cited in the file of this patent 1,637,337

UNITED STATES PATENTS 5 24,528 Allen E June 28, 1859 260,790 141,861 Dueber 2 Aug. 19, 1873 279,678

Lang July 5, 1887 Palmer Dec. 18, 1888 Burdon June 11, 1889 Cook Aug. 2, 1927 FOREIGN PATENTS Switzerland Aug. 1, 1949 Switzerland Mar. 17, 1952 

